A service to provide an answer to a question concerning a product or to provide guidance concerning a new product by telephone is in widespread use. The operator responds using a computer so as to provide prompt and accurate guidance to the user. Voice recognition software is installed on such a computer, and guidance information based on a recognition result of recognition by the voice recognition software is displayed at a display unit. Hence, the operator can provide accurate guidance while referring to guidance information corresponding to a language spoken by the user. Conventionally, for displaying such guidance information, a higher priority is given to a recognition result having a higher degree of accuracy, so as to enhance the visibility (see Japanese Patent Application Laid-Open No. 2007-108407 or Japanese Patent Application Laid-Open No. 2006-107108, for example).
However, a conventional display device only changes a display mode on the basis of the degree of accuracy of the recognition result and has a problem that guidance information still may not be presented efficiently to the operator.